In recent years there has been an increase in manufacturing of firearms, in particular pistols, having a frame/body made of injected polymeric components. Such pistols are typically lighter than pistols of same design and however comprising a metal made frame. Yet other advantages of a polymeric body are for example, corrosion resistance, improved grip, etc.
However, to date it is required that some components of the pistol still be made of metal, for example load and pressure bearing components, etc.
One such example is disclosed in U.S. Pat. No. 6,993,864 directed to a front guide mechanism for a compact semiautomatic pistol includes a pair of forward guide rails, which are normally separate from the front guide. Additionally, the front guide includes transverse ribs on the sides of the front guide, which engage mating slots in the polymeric frame of the pistol and secure the block to the frame. The guide rails and transverse ribs are separated by a space or discontinuity on the side wall of the front guide. The guide rails include chamfered front and rear edge surfaces and arcuate, convex bottom surfaces. The above-mentioned features function to create a durable front guide that allows for the construction of a pistol that is more compact than prior art designs.
Another example is disclosed in U.S. Pat. No. 5,669,169 directed to a handgun having a polymeric frame with metallic rails that are inserted within the frame after the frame has been formed by a molding process. The rails are inserted into recesses formed in a channel within the frame, before the frame has completely cooled and contracted. The rails comprise a pair of front rails and a pair of rear rails. The rear pair of rails are positioned within rear recesses and held in place by the sear block. The front pair of rails are positioned within front recesses and held in place by a plurality of metallic parts. The parts include a horseshoe, an unlock block, and a spreader block that are positioned between and matingly engage the front rails, thus securing them within their respective recesses.